European Commission Grants Orphan Medicinal Product Designation to Nektar's Amphotericin B Inhalation Powder (ABIP) for the Prevention of Pulmonary Fungal Infections in Patients Deemed At Risk

Nektar Therapeutics (Nasdaq:NKTR) announced today that
its Amphotericin B Inhalation Powder (ABIP) product has been granted
orphan medicinal product designation by the European Commission for
the prevention of pulmonary fungal infections in patients deemed at
risk. This designation is based on a recommendation from the Committee
for Orphan Medicinal Products (COMP) of the European Medicines Agency
(EMEA).
"Prevention of these serious fungal infections in the lung is a
major priority, given the increasing incidence of invasive pulmonary
aspergillosis in immunosuppressed patients," said Dr. David Denning,
professor of medicine and medical mycology at the University of
Manchester. "Any therapy that reduces the incidence of invasive
pulmonary aspergillosis in particular is welcome, as these infections
are frequently fatal, and can be expensive to treat."
According to the EMEA, orphan medicinal products are for
diagnosing, preventing or treating life-threatening or very serious
conditions that are rare and affect less than five of every 10,000
persons in the European Union (EU). An orphan drug designation
provides 10 years of potential market exclusivity if the product
candidate is approved for marketing in the EU. It also allows for
regulatory assistance in preparing the marketing application, free
protocol assistance to optimize clinical development, reduced
regulatory fees associated with applying for marketing approval and
direct access to the centralized procedure for Marketing Authorization
Application through the EMEA.
"We are pleased to make continued progress in our ABIP program and
look forward to using the scientific guidance and assistance available
through the EMEA's Orphan Medicinal Drug Program," said David
Johnston, Nektar senior vice president of research and development.
"ABIP holds the promise of preventing fatal fungal infections that
start in the lungs, can be very difficult to treat, and are associated
with extremely high mortality rates in spite of currently available
treatments."
In the U.S., the Food and Drug Administration (FDA) granted both
Fast Track designation and Orphan Drug designation to ABIP for
prevention of pulmonary fungal infections in patients at risk for
aspergillosis due to immunosuppressive therapy.

About Amphotericin B Inhalation Powder (ABIP)

ABIP is under development for the prevention of pulmonary fungal
infections such as aspergillosis in high-risk immunosuppressed
patients. The product is designed to target the site of infection
directly with a novel formulation of amphotericin B, a broad spectrum,
fungicidal drug. Nektar's innovative formulation and pulmonary
delivery method could potentially eliminate systemic, dose-limiting
toxicities found with current formulations of amphotericin B that are
delivered intravenously.
Immunosuppressed patients, for example, those receiving organ or
stem cell transplants, or chemotherapy or radiation therapy for
hematologic malignancies -- are vulnerable to opportunistic fungal
infections, such as aspergillosis, which start in the lungs and spread
throughout the body. Aspergillosis has a mortality rate of over 50%,
and in some immunosuppressed patient groups the mortality rate may be
near 100%.(1) Using ABIP for patients at risk of developing the
infection may potentially reduce the incidence of these infections, as
well as associated high morbidity and mortality and significant
treatment costs.
ABIP recently completed a multi-dose, dose escalation clinical
study in preparation for pivotal trials to begin in 2007.

(1) Lin et al. 2001, Aspergillosis Case-Fatality Rate: Systematic
Review of the Literature. Clinical Infectious Disease, 32: 358-366.

NOTE TO EDITORS: Information on ABIP data presented at major
congresses by Nektar scientists is available by contacting Nektar
Corporate Communications at 650-631-4954.

About Nektar

Nektar Therapeutics is a biopharmaceutical company that develops
and enables differentiated therapeutics with its industry-leading drug
delivery technologies, expertise and manufacturing capabilities.
Nektar technology and know-how have enabled nine approved products for
partners, which include the world's leading pharmaceutical and
biotechnology companies. Nektar also develops its own products by
applying its drug delivery technologies and expertise to existing
medicines to enhance performance, such as improving efficacy, safety
and compliance.

This release contains forward-looking statements that reflect
management's current views as to Nektar's clinical plans and
expectations for a product under development, the potential for new
product efficacy, safety, compliance, and economic benefits for
patients, and the value and benefits of Nektar technologies such as
ABIP. These forward-looking statements involve substantial risks and
uncertainties including, without limitation, the uncertainty and
expense of the clinical trial programs and uncertain regulatory
approval process for new products (including those granted Orphan
Medicinal Product Designation designation by EMEA) and the commercial
feasibility of early stage development products such as ABIP. A
further description of other important risks and uncertainties related
to these forward-looking statements are detailed in Nektar's reports
and other filings with the SEC, including its Annual Report on Form
10-K for the year ended December 2005 and its Quarterly Report on 10-Q
for the quarter ended March 31, 2006. Actual results could differ
materially from these forward-looking statements. Nektar assumes no
obligation to update any forward-looking statements contained in this
release as the result of new information or future events or
developments that may occur after the date of this release.